You can make Volumetric objects as light sources, and you can place axis-based additional lights within them as well. The results can be stunning, once you get the hang of the Volumetric settings in Attributes, but it's like going back in time with the long rendering time necessary. Still, the Volumetric object will attenuate the lights in neat ways.

here is another old test of Volumetric objects as light sources. All of these are several years old, and took ages to render on my circa 2001 PC. With my new dell I-5 laptop, I am finding that I can pursue this avenue faster...again, NO TEXTURES are in use here.

As you can see in light object.jpg, the IFD (or IFA,also)light requester has this look: for intensity there is an individual controls for every channel. In this way, I can set various values (e.g. R=655, G=655, B=255).

The light requester in IFW has not separated controsols for inntensity. With intensity at 500 I've R=500, G=500, B=500 values.